Gastrointestinal endoscopy is the first choice for the examination of digestive tract diseases, in which painless gastrointestinal endoscopy is widely understood and accepted by the population. Studies have shown that, the Sedation related adverse events (SRAEs) is one of the most commonly complications in gastrointestinal endoscopy, and it generally manifests as unstable hemodynamics and oxygen desaturation. Even though patients applied for gastrointestinal endoscopy have been evaluated by clinic anesthesia preoperative evaluation, sedation related adverse events happen occasionally during perioperative period, which may have a negative impact on patients' safety and physicians' procedure if not timely and properly handled. This paper describes the risk factors, the possible mechanism, and common adverse events of SRAEs. SRAEs may also have a certain impact on respiratory tract infection in patients after painless endoscopic diagnosis and treatment. Now, we'd like to review the research status about SRAEs in gastrointestinal endoscopy, to provide guidance and help for the early diagnosis and treatment of SRAEs.